Ensure install.log Is Retained for 365 or More Days and No Maximum Size

MediumLevel 1Automatedmacos

Description

macOS writes information pertaining to system-related events to the file /var/log/install.log and has a configurable retention policy for this file. The default logging setting limits the file size of the logs and the maximum size for all logs. The default allows for an errant application to fill the log files and does not enforce sufficient log retention. Audit: Requires ttl >= 365 and no all_max= setting in /etc/asl/com.apple.install.

How it is checked

Audit method: Shell command

shell

f=/etc/asl/com.apple.install
[ -r "$f" ] || exit 1
t=$(/usr/bin/grep -io 'ttl=[0-9]*' "$f" | /usr/bin/head -1 | /usr/bin/cut -d= -f2)
if [ -n "$t" ] && [ "$t" -ge 365 ] && ! /usr/bin/grep -qi 'all_max=' "$f"; then echo compliant; else echo "ttl=${t:-unset}; all_max present or ttl < 365"; fi

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Terminal: Edit the /etc/asl/com.apple.install file and add or modify the ttl value to 365 or greater on the file line. Also, remove the all_max= setting and value from the file line.

Properties

Operating systems: macos-15
Tags: macoslogging-auditing
Reference: CIS Apple macOS 15.0 Sequoia Benchmark v2.1.0 - 3.3 Ensure install.log Is Retained for 365 or More Days and No Maximum Size

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target macos